Determining the characteristics of contact interaction between the two-row windshield wiper and a curvilinear glass surface

Abstract

Among the evaluation criteria for determining the efficiency of vehicle windshield cleaning, the pressure distribution of the wiper rubber brush on the glass surface is important. The problem is the lack of this indicator standardization by the United Nations Economic Commission for Europe Rules (UNECE) regarding the windshield wipers certification. The inhomogeneity of the pressure distribution of the conventional wiper (the object of research) is additionally due to the mobility of the links of its mechanism and the plasticity of the rubber brush together with the blade. The pressure value should not be more than 30–50 kPa (33.4 kPa was recorded for the immobilized wiper case), and the external normal load on the frame should be kept within 20...30 N. Under a load of 24 N, the wiper blade was deformed by 1.48 mm (according to R43, it cannot exceed 1.5 mm). Further loading of the wiper frame causes two types of plastic deformation: local and global (loss of the rubber brush shape). Local displacements have increased to 1.82 mm, and the shape of the blade has acquired a "sliced" character, which causes thin jets of dirt. Global ones led to the rubber brush bending with the gap between it and the glass (5.7 mm) and caused the blind zone appearance. Models to mathematically predict layer-by-layer deformations of a conventional wiper were investigated. A model of a double-row blade with separate brushes was built, which enables the parallelization of water flows and explains the increase in the efficiency of its design. Hydrodynamic tests showed 1.58 times greater effectiveness compared to a classic single-row blade: the water flow rate was 15.61 vs 9.86 m/s. This technological advancement is the subject of a patent and a possible working prototype